I am quite certain that the synching only works for ebooks purchased from Amazon and not for any content you load yourself onto the Kindle. I also know no way of loading your own ebooks into the Kindle iPhone app. You can use your own mobi ebooks with the Kindle and Kindle for PC however.

Kindle for BB does work with your own MOBI ebooks (just copy them to your memory card under /kindle/eBooks/), see Kindle For BlackBerry Now Available For Download. A similar approach also works on an iPhone, but you have to use 3rd party software to get the MOBI files in the right directory.

Also I don't know how wireless sync the books. But I am able to keep my books synced by manually copying the ".mbp" file between the kindle, PC, BB, iPhone will keep the book in sync ( just for the bookmarks and current page).

Also I don't know how wireless sync the books. But I am able to keep my books synced by manually copying the ".mbp" file between the kindle, PC, BB, iPhone will keep the book in sync ( just for the bookmarks and current page).